GTA02 Battery Capacity (Was: Re: More about the GTA02)

joerg joerg.twinklephone at
Fri Feb 15 02:35:57 CET 2008

Am Fr  15. Februar 2008 schrieb Andy Green:
> Still for quite a few embedded tasks I2C or LVTTL UART --
> let's not forget USB OTG 12Mbps host from the mini USB B connector --
> will be enough to make a practical solution though.
Good point! If i need additional GPIO, so what. I got I2C, so i just chain up 
some with a dirt cheap chip.
The interfacing of the smart battery in GTA01 shouldn't be a big thing this 
Homebrew I2C->GPIO driver, patching GPIO_Bat DEF in src for GTA02 smartbat 

So real issue left for some projects is "which power should i use" (especially 
for those devices that don't do their own power-down).

And i wonder whether there will be *good* (near circuit diagram) specs for the 
connectors. I.E.: 
*-what kind of OverVoltage-Protection (clamp-diodes etc) / HF-blocking / 
ground potential..., can i expect behind any external connector. 
*-What exactly is the impedance (R, C) of headset out, what are the absolute 
maximum ratings (so i may figure out e.g. whether the headset out makes for a 
high-quality (HiFi) 1,5V at 10K line out, or should i plan for a 56R load 
instead of the standard 10k-50k).
*-USB-host power shortcircuit...? Will it blow my battery or whole NEO up in 
smoke? ;-). 
For questions like these i'm used to refer to a c.diagram. If they are 
answered verbatim somewhere, i'm fine with it.


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